Remove L2CA_ConfigReq in client code

Let L2CAP do this for you.

HIDD used to send anothe ConfigReq if the remote HIDH wants a different
QOS. We drop this adjustment for now. QOS is not used. Regard this as a
normal config error. This simplifies the workflow.

Bug: 159815595
Tag: #refactor
Test: compile & verify basic functions working
Change-Id: Ic3ff08a4b876462fec697ffa8a09fc8bca943603